The Americans with Disabilities Act (ADA) has mandated that signs which are to be utilized for “permanent room identification” in public facilities are to have lettering which is to be raised at least 1/32 inch from the background of the sign. Further required by the ADA is the use of Grade II Braille on “permanent room identification” signs which is also to be raised at least 1/32 inch from the background of the sign.
Displays, such as signs, having raised characters or images (i.e., “relief” portions) with colors different from a background color thereof are known. Often, such displays are referred to as “one-off” displays because the raised characters and/or images are unique to each display. For example, hotels often mount a sign next to each room to indicate the number of each room. Because each room in a hotel conventionally has a unique number, each respective room number sign will be unique. Co-assigned U.S. Pat. No. 6,238,609 describes methods of producing one-off displays using thermosetting resins, and is incorporated herein by reference in its entirety.
A known method of fabricating displays with raised images and/or characters is to apply preformed characters or images of one color to a substrate of another color. Another known method is to produce an article having images or characters in relief therewith, and then to apply different colors to the raised portions, such as by painting, staining, silk-screening, and the like (often referred to as “tipping”). Unfortunately, these methods may be somewhat labor intensive and may be prone to fabrication errors. Furthermore, displays produced via conventional methods may be rendered aesthetically unpleasing as a result of wear or damage. For example, paint may chip off of a raised portion of a display or an attached raised portion may become detached from the display through wear and/or vandalism.
Displays with raised portions formed by casting a polymeric resin into a mold having one or more recesses can be adversely affected by resin shrinkage during the curing process. Shrinkage of raised portions during curing can induce shear stress that can damage the raised portions and/or display. In addition, displays with raised portions formed by casting a polymeric resin into a mold having one or more recesses can be adversely affected by the presence of air bubbles and voids. For example, polyester resin, by nature, holds air bubbles tenaciously.
Increasingly, displays are being fabricated with thermosetting polymeric resins because of the durability and longevity that thermosetting resins exhibit. Unfortunately, there are a number of issues that make thermosetting resins undesirable as a molding material. For example, because thermosetting resins require the use of various solvents, volatile organic chemicals (VOCs) are emitted during processing, which may present safety problems as well as environmental problems. In addition, thermosetting resins can be difficult to break down and recycle at the end of the life of a product incorporating them.